Implantation of artificial valves are performed in a varietY of different ways but basically adhere to the same basic principles. Generally, valve implantation techniques are performed in the following way. The natural valve and valve tissue are excised or excluded (occasionally the posterior leaflet of the mitral valve and the subvalvular mechanism are left intact--surgeon's choice). Following excision of the valve, sutures are placed into the annulus of the natural valve and then the same sutures are placed into the sewing ring of the artificial valve. The type of suture used, the use or nonuse of pledgets, the type of stitch and the order in which the sutures are placed are unimportant (through the sewing ring of the artificial valve first or the annulus of the natural valve first).